llvm/lib/Target/ARC/ARCMCInstLower.cpp

   1 //===- ARCMCInstLower.cpp - ARC MachineInstr to MCInst ----------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// This file contains code to lower ARC MachineInstrs to their
  11 /// corresponding MCInst records.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "ARCMCInstLower.h"
  16 #include "llvm/CodeGen/AsmPrinter.h"
  17 #include "llvm/CodeGen/MachineFunction.h"
  18 #include "llvm/CodeGen/MachineInstr.h"
  19 #include "llvm/CodeGen/MachineOperand.h"
  20 #include "llvm/MC/MCContext.h"
  21 #include "llvm/MC/MCExpr.h"
  22 #include "llvm/MC/MCInst.h"
  23
  24 using namespace llvm;
  25
  26 ARCMCInstLower::ARCMCInstLower(MCContext *C, AsmPrinter &AsmPrinter)
  27     : Ctx(C), Printer(AsmPrinter) {}
  28
  29 MCOperand ARCMCInstLower::LowerSymbolOperand(const MachineOperand &MO,
  30                                              MachineOperandType MOTy,
  31                                              unsigned Offset) const {
  32   MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
  33   const MCSymbol *Symbol;
  34
  35   switch (MOTy) {
  36   case MachineOperand::MO_MachineBasicBlock:
  37     Symbol = MO.getMBB()->getSymbol();
  38     break;
  39   case MachineOperand::MO_GlobalAddress:
  40     Symbol = Printer.getSymbol(MO.getGlobal());
  41     Offset += MO.getOffset();
  42     break;
  43   case MachineOperand::MO_BlockAddress:
  44     Symbol = Printer.GetBlockAddressSymbol(MO.getBlockAddress());
  45     Offset += MO.getOffset();
  46     break;
  47   case MachineOperand::MO_ExternalSymbol:
  48     Symbol = Printer.GetExternalSymbolSymbol(MO.getSymbolName());
  49     Offset += MO.getOffset();
  50     break;
  51   case MachineOperand::MO_JumpTableIndex:
  52     Symbol = Printer.GetJTISymbol(MO.getIndex());
  53     break;
  54   case MachineOperand::MO_ConstantPoolIndex:
  55     Symbol = Printer.GetCPISymbol(MO.getIndex());
  56     Offset += MO.getOffset();
  57     break;
  58   default:
  59     llvm_unreachable("<unknown operand type>");
  60   }
  61
  62   assert(Symbol && "Symbol creation failed.\n");
  63   const MCSymbolRefExpr *MCSym = MCSymbolRefExpr::create(Symbol, Kind, *Ctx);
  64
  65   if (!Offset)
  66     return MCOperand::createExpr(MCSym);
  67
  68   // Assume offset is never negative.
  69   assert(Offset > 0);
  70
  71   const MCConstantExpr *OffsetExpr = MCConstantExpr::create(Offset, *Ctx);
  72   const MCBinaryExpr *Add = MCBinaryExpr::createAdd(MCSym, OffsetExpr, *Ctx);
  73   return MCOperand::createExpr(Add);
  74 }
  75
  76 MCOperand ARCMCInstLower::LowerOperand(const MachineOperand &MO,
  77                                        unsigned Offset) const {
  78   MachineOperandType MOTy = MO.getType();
  79
  80   switch (MOTy) {
  81   default:
  82     llvm_unreachable("unknown operand type");
  83   case MachineOperand::MO_Register:
  84     // Ignore all implicit register operands.
  85     if (MO.isImplicit())
  86       break;
  87     return MCOperand::createReg(MO.getReg());
  88   case MachineOperand::MO_Immediate:
  89     return MCOperand::createImm(MO.getImm() + Offset);
  90   case MachineOperand::MO_MachineBasicBlock:
  91   case MachineOperand::MO_GlobalAddress:
  92   case MachineOperand::MO_ExternalSymbol:
  93   case MachineOperand::MO_JumpTableIndex:
  94   case MachineOperand::MO_ConstantPoolIndex:
  95   case MachineOperand::MO_BlockAddress:
  96     return LowerSymbolOperand(MO, MOTy, Offset);
  97   case MachineOperand::MO_RegisterMask:
  98     break;
  99   }
 100
 101   return {};
 102 }
 103
 104 void ARCMCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
 105   OutMI.setOpcode(MI->getOpcode());
 106
 107   for (const MachineOperand &MO : MI->operands()) {
 108     MCOperand MCOp = LowerOperand(MO);
 109
 110     if (MCOp.isValid())
 111       OutMI.addOperand(MCOp);
 112   }
 113 }